Oracle has asked an appeals court to decide that it does have copyright protection for its Java APIs, which Google used in the creation of its Android operating system, and thereby revive its billion-dollar suit against the firm.

Oracle’s lawyer Josh Rosenkranz told the three-judge panel of the US Court of Appeals that Google had taken “the most important, the most appealing” parts of Java to use in Android, Bloomberg reported.

The case centres on whether copyright protection should be applicable to application programming interfaces, or APIs. In the original case, the judge found that copyright didn’t cover Java’s APIs, which allow developers to write programs that work across operating systems, and said that Google had only mimicked the interfaces - not copied them outright.

"So long as the specific code used to implement a method is different, anyone is free under the Copyright Act to write his or her own code to carry out exactly the same function or specification of any methods used in the Java API," Judge William Alsup said.

However, Oracle is arguing that copyright should apply to Java APIs, telling the appeals court in a filing that Google’s argument was akin to an author copying the chapter titles and topic sentences of an advance copy of a Harry Potter book and then paraphrasing the rest and claiming it as fair use.

During 90 minutes of arguments yesterday, appeals court judges indicated they might be willing to side with Oracle on the issue of copyright protection. Circuit Judge Kathleen O’Malley said that the fact that Java was freely available to programmers and widely used didn’t mean it couldn’t get copyright protection.

They also worried that the case set a precedent for APIs that could be used in relation to software from other companies like Microsoft and Apple. O’Malley asked Google if it could have used those firms’ interfaces in an operating system as well.

“Yes, but only the command structure,” Google lawyer Bob Van Nest said. “They would have to rewrite millions of lines of code. That’s what Android did - 15 million lines of Android code are all original.”

Microsoft, NetApp and EMC have all filed written arguments supporting Oracle’s side of the copyright fight, while Rackspace and the Application Developers Alliance are on Google’s side, saying that the APIs used are just directions without any creativity.

Even if the judges decide that copyright does apply however, there will still need to be a decision on whether Google used the APIs fairly or not. Although Oracle’s legal team said the appeals court could rule on fair use, Van Nest said the issue would need to go to a trial court for a jury to decide.

In the original case, the jury couldn’t agree on whether Google had fairly used the APIs or not before Judge Alsup decided it didn’t matter because they weren’t covered by copyright anyway.

Oracle first looked for $6.1bn in damages, but that estimate was thrown out by the judge before it ever got to trial. However, the firm could still seek over a billion dollars if the case is tried again. ®